Switch



Feb. 29, 1944. E, L. HORNING SQWITCH Filed Sept. 25, 1941 INVENTOR Eon/m L. HORN/NS HI ATTORNEYS UNlTED STATES PATENT SWITCH Edwin L. Horning, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application September 25, 1941, Serial No. 412,327

(BFFlCE 2 Claims.

The invention relates to improvements in electric switches and particularly electric switches of the snap action type.

It is among the objects of the present invention to provide a snap action switch having a plijacent end oi said slots being slightly greater able insulating cover which not only completely than the distance between inner, adjacent surseals the entire switch against moisture but is faces of the upwardly extending tongue poradapted to be distorted to actuate the switch tions 21a and 28a of the bracket 28. These dirthereby entirely eliminating the possibility of the ferences in dimensions just mentioned are prooperator coming into contact with any of its vided so tat when the strip 30 is placed upon electrically charged parts. the bracker, the tongue 21a of the bracket being A further object of the present invention is to received by the slot SI of the strip and the provide a sealed snap action switch 01' simple tongue 28a of the bracket being received by the structure and design, comprising a minimum slot 32 of the strip, the confined intermediate number of parts and requiring a minimum time portion of the strip 30 between said tongues will to assemble. be biased so as to be adapted to be bowed in one Further objects and advantages of the present di e tio 1 e ot er- When a d upwardly invention will be apparent from the following away from the bottom of the bracket 26, as shown description, reference being had to the accomin the fi intermediate p tion of panying drawing whereinapreferredembodlment the strip will urge the end' portions of the 01' one form of the present invention is clearly Strip in the opposite direction or toward the bothow tom of the bracket 26. In the position as shown In the drawing: in Fig. 2, the shape 01' the strip 30 is such that Fig. 1 is a plan view of the switch with its casthe contact 40, carried at one end of the St ip. ing or cover shown in section. the view being 2 w e gage with its cooperati g stationary contaken along the line ll or Fig.2; tact 25. However, the contact 4! attached to the Fig. 2 is a side view or the switch, the cover opposite n f the s p 30 l li in li nment or casing thereof being shown in section. In this with b paced from its cooper Contact view the switch is shown in a position in which n Order to Cause n a e nt of Contact 4! with One Of its circuitsiscompleted. its cooperating contact 24 the operator must Fig. 3 is a view similar to Fig. 2, the casing or Press d maintain Dressed this end of the strip cover, however, being deformed to actuat th 30. The release of such pressure will immediately switch to close a second circuit thereof; permit s e of e strip to flex and move Fig, 4 1 i similar t F1gs 2 and 3 contact 4| out of engagement with contact 24. ever, in this View t casing cover is shown However, contact will maintain engagement deformed to actuate the switch so that all of its With its Cooperating C ac 5 as long as strip circu t are open. 30 is bowed in the direction shown in Fig. 2.

Ref -m t th drawing th numeral 20 desig- When it is desired to separate contact 40 from mat th dischaped b of t t made its cooperating contact 25, the confined or interof any suitable insulating material, This base 40 mediate portion at the strip 30 between the bracksupports three terminals 2|, 22 and 23. The ten 8t tongues a 2 11 m t be reversed in minals 2| and 23 provide stationary contacts 24 curvature from that shown in Figs. 1 and 2. This and 25 respectively while the terminal 22, interis done by exerting p ssure upon this confined posed between terminals 1 and 23 provides portion of the strip 30 urging it downwardly or means for ecuring the bracket 28 upgn the in toward the bottom of the bracket 26. When thlS sulating base 20. This bracket as shown in Figs. confined porti n of the ip ss m s the position 2, 3 and 4 is U-shaped having two upstanding as shown in Fig. 4. or more specifically, when it spaced arms 21 and 28 Each arm has a tongueis flexed downwardly tOWEId the bottom of the like extension, the one of arm 21 being designated bracket 26 t e ds 1 th st w ll be qui y by the numeral 21a and the tongue-like extenshifted in the opposite direction or away from sion of arm 28 being designated by the numeral the stationary contacts 24 and 25 so that con 2la. tact 40 will thus be moved out oi engagement The movable element or the switch which is with. its cooperating contact 25 and therefore all adapted to move with a snap action is in the circuits of the switch are broken. form of a flexible metallic strip 30 carried by the A flexible pigtail connection 45 has its one end bracket 26. This metallic strip is attached to and carried by the bracket in the following manner: Elongated slots 3| and 32 are provided in the strips 30, the distance between the inner, ad-

connected to the strip 80 adjacent the contact 40 thereon while the opposite end of said pigtail conmotion is electrically secured to the bracket 26 by the terminal screw 22.

It has been previously stated that one of the objects of the present invention is to provide a snap action switch completely sealed against moisture and adapted to be actuated without possibility of the operator coming into contact with any of its electrically charged parts.

This object is attained by providing the switch with a pliable or flexible insulating cover designated by the numeral 10. The cover iscupshaped and has an internal annular groove H adapted to receive and tightly fit about the peripheral edge of the supporting disc 20 of the switch as shown in Figs. 2, 3 and 4. The tight fit oi the groove H of the cover about the outer peripheral edge of the disc seals the interior of the switch with its operating mechanism against moisture.

The present drawing shows the switch in a form preferably adapted for use on a washing machine for controlling the motor thereof. The numeral 12 indicates in fragmentary form the casing of the washing machine. In this casing there is provided an aperture, the inner annular edge of which is indicated by the numeral 13. The annular edge portion of the casing defining this aperture 13 is received by an outer annular groove provided in the casing or cover of the switch so that the switch assembly is securely held in this aperture I3 of the washing machine casing I2.

As has been mentioned the switch casing or cover is made up of pliable insulating material such as rubber or the like. In the outer surface of the cover are provided two disc-shaped areas 15 and 16, the latter substantially co-axial of the cover. Each disc-like portion 15 and 16 of the cover has inwardly extending lugs designated by the numerals 11 and 18 respectively. The disc-like portion 15 with its lug H lies over and in alignment with the end of the flexible metal strip 30 carrying the contact 4|. Disclike portion 16 of the cover and its inwardly extending lug-portion 18 lies over and in alignment with the confined portion of the strip at between the upwardly extending arms 21 and 28 of the bracket 26. When pressure is exerted upon the disc-like portion I to distort this part of the pliable switch cover or casing as shown in Fig. 3, the end of the metal strip 30 carrying contact 4| will be urged toward the stationary contact 24 so that the contact 41 on strip 30 will engage said stationary contact. As has been said before, movement of this end of the strip 30 will cause flexing of the confined por= tion of said strip between the upstanding arm of bracket 26 in the opposite direction or away from the bottom portion of the bracket 26 resulting in a sudden flexure of the end of the strip 30 carrying contact 40 toward the stationary the disc-like area 15 of the switch casing or cover to distort it, as shown in Fig. 3, engagement of switch contacts 25 and 40, will be maintained. However, as soon as such pressure is released by the operator, contacts 4| and 24 will be separated.

From the drawings and from the aforegoing description it may clearly be seen that applicant has provided an electric switch completely sealed against moisture. A switch provided with a pliable insulating cover of blister-like construction which may be distorted to operate the switch to close and open its circuits without any danger of the operator coming into contact with any of its electrically charged parts. This is particularly advantageous where the switch is used in connection with a washing machine for controlling the operation of the motor thereof for usually the floor about the washing machine is wet which is conducive .to dangerous shock to the operator if in any way he might come into contact with a charged part of a control switch.

Applicant has provided asturdy switch absolutely safe against electrical shock and of simple structure and design, comprising a minimum number of parts in its make-up and consequently requiring a minimum amount of time for its assembly. While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A snap action switch comprising-in combination, an insulating base; three aligned terminals on said base; a bracket secured to the base by the central terminal; a flexible strip secured to the bracket so as to compress and bias an area of said strip intermediate its ends; a contact on each end of the strip, only one contact engaging its terminal when the biased portion oi the strip is bowed in one direction, the other contact on the strip engaging its terminal only while pressure is exerted upon that end of the strip, both contacts being spaced from their respective terminals when the biased portion oi the strip is bowed in the other or opposite direction; and a flexible, electrical connection between the center terminal and the strip.

2. A snap action switch comprising in combination, an insulating base, three aligned terminals on said base; a U-shaped bracket secured tc said base by the one, center terminal; a flexible strip anchored to the two upstanding arms oi the U-shaped bracket so as to bias the portion contact 25 so that said contact 40 will engage with said stationary contact 25 as shown in Fig. 3. As long as the operator exerts pressure on of the strip between said two upstanding arms; a contact on each end of the flexible strip adapted to engage the respective second and third or outer terminals, the one, while the biased pr. tion of the switch is bowed away from the center terminal, the other contact only while pressure is exerted upon that end of the flexible strip; and a flexible connection between the said center terminal and the strip.

EDWIN L. HORNING. 

